Table 8.

Research comparing specific groups of participants

1	Can differences in e.g. gaze behaviour or pupil size be attributed to differences in eye-tracking data quality between groups? Determine and report data quality for the different groups and compare them, including data and trial loss for each group reported separately.
2	Determine whether there is a relation between data quality and the outcome measure of interest (within and between groups).
3	For pupil-size studies: consider that the baseline pupil size may differ between older and younger participants.